Dontcha hate auto correct?
I'd start slowly incrementing light. Perhaps start 15-20 minutes added in the morning every two or three days. That should do the trick.
How do you prevent non-layers from consuming excessive calcium?
Understandable about the affinity to Nutrena. I am buying mostly Nutrena now that our feed co-op isn't active.
I spent 32 years at Ford and though I've had several European cars, I've had dozens of Ford cars and trucks - all the way from Escorts and Focus to F-700s.
I went on an Easter hunt yesterday. I may need to do more exploring before the freezing weather returns. I have lots of pullets that look like they should be laying with only one nest in their building and only one egg so far.
I'll broach the subject of excess calcium for non-layers below.
You sound just like all the old timers that say they feed layer to all their birds and never had a problem.
Hopefully, your young birds aren't eating layer. It is hard enough on roosters and molting hens but chicks definitely can't have that much calcium. Layer is around 4% calcium. Birds to 6 weeks need about 0.8 percent calcium. 6-14 weeks - 0.7%. 14-20 weeks - 0.6%.
It is true that some strains have a resistance to excessive calcium but the research shows that most do not.
With your love of your animals and having learned about the danger of excessive calcium, I'm surprised you don't give nutrition more concern in lieu of saving a dollar a bag on feed.
http://extension.missouri.edu/p/G8352
When most people have a chicken die, they don't get a necropsy and never know that it was kidney damage.
Think about all the things chickens need nutritionally, whether that be amino acids, fats, carbohydrates, vitamins and minerals.
With chickens needing a diet requiring carbohydrates, fatty acids, 13 essential amino acids, 13 vitamins, 12 minerals Doesn't it make sense that a single mineral shouldn't make up 4% of all that intake for a bird not needing it to build egg shells?
If that doesn't make sense, how about the research that shows kidney damage in birds not needing the excessive calcium to build shells?
Chickens have 2 kidneys, each with 3 segments. As long as there are 2 functioning segments, the birds appear normal and continue to lay eggs. When one of the last 2 segments becomes dysfunctional, the bird will die within 24 hours with no other symptoms.
http://nhjy.hzau.edu.cn/kech/synkx/dong/2bao/UrolithiasisChina.pdf
http://www.neobio.biz/database/n-5data5-2/n-5data5-2-7.pdf
http://www.hyline.com/aspx/redbook/redbook.aspx?s=5&p=36
http://www.worldpoultry.net/Breeder...-damage-is-emerging-in-laying-hens-WP008719W/
On poultry farms that don't feed roosters and hens separately, roosters die at 4 times the rate of hens.
http://www.thepoultrysite.com/articles/2337/urolithiasis-in-male-broiler-breeders/
https://www.ncbi.nlm.nih.gov/pubmed/10780656
https://www.ncbi.nlm.nih.gov/pubmed/12530920
http://www.reproduction-online.org/content/early/2011/06/13/REP-11-0131.full.pdf